As well known, in computer systems where a UNIX (Registered Trade Mark) is used as an OS, there are prepared a TAR (Tape Archive/Restore) command and a CPIO (CoPy Input/Output) command as commands (utility programs) for recording files onto a recording medium.
The TAR command is a command for transferring various files stored in, e.g., a magnetic disc unit to a magnetic tape unit as they are to record such files as backups. To the contrary, the CPIO command is a command for recording (copying) not only individual files but also all file systems by the so-called CPIO format in which they are collected into one archive (stack) file.
In a data recording method using the CPIO command, various files stored in the magnetic disc unit are caused to be backed up in the magnetic tape unit. In addition, such a data recording method is used when shifting files between different platforms, and can cope with a file size up to 8 gigabytes at the maximum in the system.
However, as symbolized by realization of broad band of internet, etc., recently there is a tendency such that capacity of data to be handled becomes gigantic. For example, as for moving picture data, etc. which exceeds 8 G bytes, it is impossible to cope with such picture data by the conventional data recording method using the CPIO command. For this reason, technologies capable of recording or reproducing even a file of size exceeding a conventional size in a manner in conformity with the format of the CPIO are expected.